mpmt_os2_child.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#define CORE_PRIVATE
#define INCL_NOPMAPI
#define INCL_DOS
#define INCL_DOSERRORS

#include "ap_config.h"
#include "httpd.h"
#include "mpm_default.h"
#include "http_main.h"
#include "http_log.h"
#include "http_config.h"
#include "http_core.h"		/* for get_remote_host */
#include "http_connection.h"
#include "mpm.h"
#include "ap_mpm.h"
#include "ap_listen.h"
#include "apr_portable.h"
#include "apr_poll.h"
#include "mpm_common.h"
#include "apr_strings.h"
#include <os2.h>
#include <process.h>

/* XXXXXX move these to header file private to this MPM */

/* We don't need many processes, 
 * they're only for redundancy in the event of a crash 
 */
#define HARD_SERVER_LIMIT 10

/* Limit on the total number of threads per process
 */
#ifndef HARD_THREAD_LIMIT
#define HARD_THREAD_LIMIT 256
#endif

#define ID_FROM_CHILD_THREAD(c, t)    ((c * HARD_THREAD_LIMIT) + t)

typedef struct {
    apr_pool_t *pconn;
    apr_socket_t *conn_sd;
} worker_args_t;

#define WORKTYPE_CONN 0
#define WORKTYPE_EXIT 1

static apr_pool_t *pchild = NULL;
static int child_slot;
static int shutdown_pending = 0;
extern int ap_my_generation;
static int volatile is_graceful = 1;
HEV shutdown_event; /* signaled when this child is shutting down */

/* grab some MPM globals */
extern int ap_min_spare_threads;
extern int ap_max_spare_threads;
extern HMTX ap_mpm_accept_mutex;

static void worker_main(void *vpArg);
static void clean_child_exit(int code);
static void set_signals();
static void server_maintenance(void *vpArg);


static void clean_child_exit(int code)
{
    if (pchild) {
	apr_pool_destroy(pchild);
    }

    exit(code);
}



void ap_mpm_child_main(apr_pool_t *pconf)
{
    ap_listen_rec *lr = NULL;
    ap_listen_rec *first_lr = NULL;
    int requests_this_child = 0;
    apr_socket_t *sd = ap_listeners->sd;
    int nsds, rv = 0;
    unsigned long ulTimes;
    int my_pid = getpid();
    ULONG rc, c;
    HQUEUE workq;
    apr_pollfd_t *pollset;
    int num_listeners;
    TID server_maint_tid;
    void *sb_mem;

    /* Stop Ctrl-C/Ctrl-Break signals going to child processes */
    DosSetSignalExceptionFocus(0, &ulTimes);
    set_signals();

    /* Create pool for child */
    apr_pool_create(&pchild, pconf);

    ap_run_child_init(pchild, ap_server_conf);

    /* Create an event semaphore used to trigger other threads to shutdown */
    rc = DosCreateEventSem(NULL, &shutdown_event, 0, FALSE);

    if (rc) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
                     "unable to create shutdown semaphore, exiting");
        clean_child_exit(APEXIT_CHILDFATAL);
    }

    /* Gain access to the scoreboard. */
    rc = DosGetNamedSharedMem(&sb_mem, ap_scoreboard_fname,
                              PAG_READ|PAG_WRITE);

    if (rc) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
                     "scoreboard not readable in child, exiting");
        clean_child_exit(APEXIT_CHILDFATAL);
    }

    ap_calc_scoreboard_size();
    ap_init_scoreboard(sb_mem);

    /* Gain access to the accpet mutex */
    rc = DosOpenMutexSem(NULL, &ap_mpm_accept_mutex);

    if (rc) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
                     "accept mutex couldn't be accessed in child, exiting");
        clean_child_exit(APEXIT_CHILDFATAL);
    }

    /* Find our pid in the scoreboard so we know what slot our parent allocated us */
    for (child_slot = 0; ap_scoreboard_image->parent[child_slot].pid != my_pid && child_slot < HARD_SERVER_LIMIT; child_slot++);

    if (child_slot == HARD_SERVER_LIMIT) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
                     "child pid not found in scoreboard, exiting");
        clean_child_exit(APEXIT_CHILDFATAL);
    }

    ap_my_generation = ap_scoreboard_image->parent[child_slot].generation;
    memset(ap_scoreboard_image->servers[child_slot], 0, sizeof(worker_score) * HARD_THREAD_LIMIT);

    /* Set up an OS/2 queue for passing connections & termination requests
     * to worker threads
     */
    rc = DosCreateQueue(&workq, QUE_FIFO, apr_psprintf(pchild, "/queues/httpd/work.%d", my_pid));

    if (rc) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
                     "unable to create work queue, exiting");
        clean_child_exit(APEXIT_CHILDFATAL);
    }

    /* Create initial pool of worker threads */
    for (c = 0; c < ap_min_spare_threads; c++) {
//        ap_scoreboard_image->servers[child_slot][c].tid = _beginthread(worker_main, NULL, 128*1024, (void *)c);
    }

    /* Start maintenance thread */
    server_maint_tid = _beginthread(server_maintenance, NULL, 32768, NULL);

    /* Set up poll */
    for (num_listeners = 0, lr = ap_listeners; lr; lr = lr->next) {
        num_listeners++;
    }

    apr_poll_setup(&pollset, num_listeners, pchild);

    for (lr = ap_listeners; lr; lr = lr->next) {
        apr_poll_socket_add(pollset, lr->sd, APR_POLLIN);
    }

    /* Main connection accept loop */
    do {
        apr_pool_t *pconn;
        worker_args_t *worker_args;

        apr_pool_create(&pconn, pchild);
        worker_args = apr_palloc(pconn, sizeof(worker_args_t));
        worker_args->pconn = pconn;

        if (num_listeners == 1) {
            rv = apr_accept(&worker_args->conn_sd, ap_listeners->sd, pconn);
        } else {
            rc = DosRequestMutexSem(ap_mpm_accept_mutex, SEM_INDEFINITE_WAIT);

            if (shutdown_pending) {
                DosReleaseMutexSem(ap_mpm_accept_mutex);
                break;
            }

            rv = APR_FROM_OS_ERROR(rc);

            if (rv == APR_SUCCESS) {
                rv = apr_poll(pollset, num_listeners, &nsds, -1);
                DosReleaseMutexSem(ap_mpm_accept_mutex);
            }

            if (rv == APR_SUCCESS) {
                if (first_lr == NULL) {
                    first_lr = ap_listeners;
                }

                lr = first_lr;

                do {
                    apr_int16_t event;

                    apr_poll_revents_get(&event, lr->sd, pollset);

                    if (event == APR_POLLIN) {
                        apr_sockaddr_t *sa;
                        apr_port_t port;
                        apr_socket_addr_get(&sa, APR_LOCAL, lr->sd);
                        apr_sockaddr_port_get(&port, sa);
                        first_lr = lr->next;
                        break;
                    }
                    lr = lr->next;

                    if (!lr) {
                        lr = ap_listeners;
                    }
                } while (lr != first_lr);

                if (lr == first_lr) {
                    continue;
                }

                sd = lr->sd;
                rv = apr_accept(&worker_args->conn_sd, sd, pconn);
            }